Process for the production of alcohols

ABSTRACT

The present invention provides a process for the production of aldehydes and/or alcohols, which process comprises the steps of: (a) reacting an oxygenate and/or olefinic feed in a reactor in the presence of a molecular sieve catalyst to form an effluent comprising olefins, comprising propylene; (b) separating the effluent comprising olefins as obtained in step (a) into at least a first olefinic product fraction comprising propylene and a second olefinic product fraction; (c) subjecting at least part of the first olefinic product fraction as obtained in step (b) to a hydroformylation process to form aldehydes; (d) separating at least part of the aldehydes as obtained in step (c) into at least a first product fraction of aldehydes and a second product fraction of aldehydes; and (e) hydrogenating at least part of the aldehydes in the first and/or second product fraction of aldehydes as obtained in step (d) to form a first product fraction of alcohols and/or a second product fraction of alcohols; (f) recycling at least part of the first and/or second product fraction of alcohols obtained in step (e) to step (a).

PRIORITY CLAIM

The present application is the National Stage (§371) of InternationalApplication No. PCT/EP2012/076848, filed Dec. 21, 2012, which claimspriority from European patent application no. 11195830.2, filed Dec. 27,2011, the disclosures of which are incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to a process for the production of alcohols.

BACKGROUND OF THE INVENTION

Various processes for producing aldehyde and/or alcohol compounds by thereaction of an olefin with carbon monoxide and hydrogen in the presenceof a catalyst are known. Typically, these reactions are performed atelevated temperatures and pressures. The aldehyde and alcohol compoundsthat are produced generally correspond to compounds obtained by theaddition of a carbonyl or carbinol group, respectively, to anunsaturated carbon atom in the starting material with simultaneoussaturation of the unsaturated carbon-carbon bond. Isomerization of theolefin bond may take place to varying degrees under certain conditions;thus, as a consequence of this isomerization, a variety of products maybe obtained. These processes are typically known as hydroformylationreactions.

The catalyst employed in a hydroformylation reaction typically comprisesa transition metal, such as cobalt, platinum, rhodium or ruthenium, incomplex combination with carbon monoxide and ligand(s) such as anorganophosphine.

The following documents are representative of the earlierhydroformylation methods which use transition metal catalysts: U.S. Pat.No. 3,420,898, U.S. Pat. No. 3,501,515, U.S. Pat. No. 3,448,157, U.S.Pat. No. 3,440,291, U.S. Pat. No. 3,369,050 and U.S. Pat. No. 3,448,158.

As mentioned above, several products may be obtained. In case of forinstance the hydroformylation of propylene, a mixture of normalbutyraldehyde and iso-butyraldehyde may be formed, which through asubsequent hydrogenation may be converted to a mixture of normalbutyl-alcohol and isobutyl-alcohol. In attempts to improve theselectively of the hydroformylation reaction toward either normalbutyraldehyde and iso-butyraldehyde, attention has typically focussed ondeveloping novel catalysts and novel processes for recovering andre-using the catalyst. In particular, novel catalysts have beendeveloped which may exhibit improved selectively toward normalbutyraldehyde and optionally normal butyl-alcohol. In WO 2011/087690 A1a hydroformylation process is described using a rhodium based catalystcomprising at least two different ligand molecules. According to WO2011/087690 A1 the use of the two different ligand molecules may providea higher normal butyraldehyde over iso-butyraldehyde ratio.

A disadvantage of the process of WO 2011/087690 A1 is that it requirestwo different ligand molecules, which makes the catalyst system andaccompanying process complex and expensive.

There is a need for a process to produce aldehydes and/or alcohols at ahigh normal over iso-aldehydes or alcohol ratio or a high iso overnormal aldehydes or alcohol ratio, without the need to use complexhydroformylation catalyst(s).

SUMMARY OF THE INVENTION

According to the present invention there is provided a process for theproduction of aldehydes and/or alcohols, which process comprises thesteps of:

(a) reacting an oxygenate and/or olefinic feed in a reactor in thepresence of a molecular sieve catalyst to form an effluent comprisingolefins, comprising propylene;

(b) separating the effluent comprising olefins as obtained in step (a)into at least a first olefinic product fraction comprising propylene anda second olefinic product fraction;

(c) subjecting at least part of the first olefinic product fraction asobtained in step (b) to a hydroformylation process to form aldehydes;

(d) separating at least part of the aldehydes as obtained in step (c)into at least a first product fraction of aldehydes and a second productfraction of aldehydes; and

(e) hydrogenating at least part of the aldehydes in the first and/orsecond product fraction of aldehydes as obtained in step (d) to form afirst product fraction of alcohols and/or a second product fraction ofalcohols;

(f) recycling at least part of the first and/or second product fractionof alcohols obtained in step (e) to step (a).

In accordance with the present invention a highly effective andefficient integrated process is provided for the production of aldehydesand/or alcohols.

Preferably, the first product fraction of aldehydes as obtained in step(d) comprises isobutyl-aldehydes and the second product fraction ofaldehydes as obtained in step (d) comprises normal butyl-aldehydes,while first product fraction of alcohols as obtained in step (e)comprises isobutyl-alcohol and the second product fraction of alcoholsas obtained in step (e) comprises normal butyl-alcohol.

A major advantage of the present process is that a high selectivitytowards normal butyraldehydes and normal butyl-alcohols can beestablished without requiring an expensive catalyst system, and that theiso-butyraldehyde to normal butyraldehyde ratio, respectively theisobutyl-alcohol to normal butyl-alcohol ratio can be adjusted to meetmarket demands.

If desired, it is possible to recycle normal butyl-alcohol, obtained bythe hydrogenation of normal butyl aldehyde, to step (a) rather than theisobutyl-alcohol, obtained by the hydrogenation of isobutyl aldehyde. Inthat case, isobutyl aldehyde, respectively isobutyl-alcohol may beretrieved as a product.

A further advantage of the process according to the invention is thatthe butanol, normal butyl-alcohol or isobutyl-alcohol, recycled to step(a) is at least in part converted back to propylene, which can beprovided as part of the first olefinic fraction to prepare furtheralcohols.

Suitably, at least part of the first product fraction of alcohols,preferably comprising isobutyl-alcohol, is recycled to step (a).Preferably, the entire first product fraction of alcohols is recycled tostep (a).

Suitably, at least part of the second olefinic product fraction whichmay comprise normal butyl-alcohol as obtained in step (e) is recycled tostep (a).

Preferably, the second olefinic product fraction as obtained in step (b)is an olefinic product fraction comprising olefins have 4 or more carbonatoms. Preferably, at least part of the second olefinic product fractionas obtained in step (b) is subjected to an separate olefin crackingprocess to convert at least part of the olefins comprising 4 or morecarbon atoms to olefins having a lower carbon number, i.e. an olefinhaving n carbon atoms is cracked to at least one olefin have m carbonatoms, wherein n and m are integers and m is smaller than n. Preferably,the olefins comprising 4 or more carbon atoms are cracked to at leastethylene and propylene. At least part of the olefins thus formed isrecycled to step (b).

Preferably, at least part of the second olefinic product fractioncomprising olefins having 4 or more carbon atoms as obtained in step (b)is first fractionated to obtain at least a third olefinic productfraction comprising C4 olefins and a fourth olefinic product fractioncomprising olefins having 5 or more carbon atoms, wherein at least partof the fourth fraction is provided to the separate olefin crackingprocess, while at least part of the third olefinic product fraction isrecycled as recycle stream to step (a).

The effluent comprising olefins as obtained in step (a) may alsocomprise ethylene in addition to propylene. Ethylene is a valuablechemical feedstock. It is an advantage of the present invention that thealcohol, preferably butanol, which is recycled back to step (a) may atleast in part be converted to further ethylene. As such part of theobtained effluent in step (a) is converted to ethylene.

Preferably, the first olefinic product fraction as obtained in step (b)mainly contains propylene.

DETAILED DESCRIPTION OF THE INVENTION

In the present invention, an oxygenate feed is converted in anoxygenate-to-olefins (OTO) process and/or an olefinic feed is convertedin an olefin cracking process (OCP).

The present invention in particularly relates to a process for theconversion of oxygenates into olefins.

In step (a), an oxygenate feed and/or olefinic feed is reacted in areactor in the presence of a molecular sieve catalyst to form a effluentwhich comprises olefins and at least partially coked catalyst. Thereactor in step (a) can be an OTO reaction zone wherein at least theoxygenate feed is contacted with an oxygenate conversion catalyst underoxygenate conversion conditions, to obtain a conversion effluentcomprising lower olefins. Reference herein to an oxygenate feed is to anoxygenate-comprising feed. In the OTO reaction zone, at least part ofthe feed is converted into a product containing one or more olefins,preferably including lower olefins, in particular ethylene andpropylene.

The oxygenate used in the process according to the invention ispreferably an oxygenate which comprises at least one oxygen-bonded alkylgroup. The alkyl group preferably is a C1-C5 alkyl group, morepreferably C1-C4 alkyl group, i.e. comprises 1 to 5, respectively, 4carbon atoms; more preferably the alkyl group comprises 1 or 2 carbonatoms and most preferably one carbon atom. Examples of oxygenates thatcan be used in the oxygenate feed include alcohols and ethers. Examplesof preferred oxygenates include alcohols, such as methanol, ethanol,propanol; and dialkyl ethers, such as dimethylether, diethylether,methylethylether. Preferably, the oxygenate is methanol ordimethylether, or a mixture thereof. More preferably, the oxygenate feedcomprises methanol or dimethylether.

Preferably the oxygenate feed comprises at least 50 wt % of oxygenate,in particular methanol and/or dimethylether, based on totalhydrocarbons, more preferably at least 70 wt %.

The oxygenate feed can comprise an amount of diluent, such as nitrogenand water, preferably in the form of steam. In one embodiment, the molarratio of oxygenate to diluent is between 10:1 and 1:10, preferablybetween 4:1 and 1:2, in particular when the oxygenate is methanol andthe diluent is water (steam).

A variety of OTO processes is known for converting oxygenates such asfor instance methanol or dimethylether to an olefin-containing product,as already referred to above. One such process is described in WO-A2006/020083. Processes integrating the production of oxygenates fromsynthesis gas and their conversion to light olefins are described inUS20070203380A1 and US20070155999A1.

Catalysts suitable for converting the oxygenate feed in accordance withthe present invention include molecular sieve-catalysts. The molecularsieve catalyst suitably comprises one or more zeolite catalysts and/orone or more SAPO catalysts. Molecular sieve catalysts typically alsoinclude binder materials, matrix material and optionally fillers.Suitable matrix materials include clays, such as kaolin. Suitable bindermaterials include silica, alumina, silica-alumina, titania and zirconia,wherein silica is preferred due to its low acidity.

Molecular sieve catalysts preferably have a molecular framework of one,preferably two or more corner-sharing [TO₄] tetrahedral units, morepreferably, two or more [SiO₄], [AlO₄] and/or [PO₄] tetrahedral units.These silicon, aluminum and/or phosphorous based molecular sieves andmetal containing silicon, aluminum and/or phosphorous based molecularsieves have been described in detail in numerous publications includingfor example, U.S. Pat. No. 4,567,029. In a preferred embodiment, themolecular sieve catalysts have 8-, 10- or 12-ring structures and anaverage pore size in the range of from about 3 Å to 15 Å.

Suitable molecular sieve catalysts are silicoaluminophosphates (SAPO),such as SAPO-17, -18, -34, -35, -44, but also SAPO-5, -8, -11, -20, -31,-36, -37, -40, -41, -42, -47 and -56; aluminophosphates (AlPO) and metalsubstituted (silico)aluminophosphates (MeAlPO), wherein the Me in MeAlPOrefers to a substituted metal atom, including metal selected from one ofGroup IA, IIA, IB, IIIB, IVB, VB, VIB, VIIB, VIIIB and Lanthanide's ofthe Periodic Table of Elements, preferably Me is selected from one ofthe group consisting of Co, Cr, Cu, Fe, Ga, Ge, Mg, Mn, Ni, Sn, Ti, Znand Zr.

Preferably, the conversion of the oxygenate feed may be accomplished bythe use of an aluminosilicate-comprising catalyst, in particular azeolite-comprising catalyst. In a zeolite-comprising catalyst the amountof zeolite is suitably from 20 to 50 wt %, preferably from 35 to 45 wt%, based on total catalyst composition.

Suitable catalysts include those containing a zeolite of the ZSM group,in particular of the MFI type, such as ZSM-5, the MTT type, such asZSM-23, the TON type, such as ZSM-22, the MEL type, such as ZSM-11, theFER type. Other suitable zeolites are for example zeolites of theSTF-type, such as SSZ-35, the SFF type, such as SSZ-44 and the EU-2type, such as ZSM-48.

Aluminosilicates-comprising catalyst, and in particularzeolite-comprising catalyst are preferred when an olefinic co-feed isfed to the oxygenate conversion zone together with oxygenate, forincreased production of ethylene and propylene.

Preferred catalysts comprise a more-dimensional zeolite, in particularof the MFI type, more in particular ZSM-5, or of the MEL type, such aszeolite ZSM-11. Such zeolites are particularly suitable for convertingolefins, including iso-olefins, to ethylene and/or propylene. Thezeolite having more-dimensional channels has intersecting channels in atleast two directions. So, for example, the channel structure is formedof substantially parallel channels in a first direction, andsubstantially parallel channels in a second direction, wherein channelsin the first and second directions intersect. Intersections with afurther channel type are also possible. Preferably, the channels in atleast one of the directions are 10-membered ring channels. A preferredMFI-type zeolite has a Silica-to-Alumina ratio (SAR) of at least 60,preferably at least 80.

Particular catalysts may include catalysts comprising one or morezeolite having one-dimensional 10-membered ring channels, i.e.one-dimensional 10-membered ring channels, which are not intersected byother channels. Preferred examples are zeolites of the MTT and/or TONtype.

In a preferred embodiment the catalyst comprises in addition to one ormore one-dimensional zeolites having 10-membered ring channels, such asof the MTT and/or TON type, a more-dimensional zeolite, in particular ofthe MFI type, more in particular ZSM-5, or of the MEL type, such aszeolite ZSM-11.

The catalyst may comprise phosphorus as such or in a compound, i.e.phosphorus other than any phosphorus included in the framework of themolecular sieve. It is preferred that an MEL or MFI-type zeolitescomprising catalyst additionally comprises phosphorus. The phosphorusmay be introduced by pre-treating the MEL or MFI-type zeolites prior toformulating the catalyst and/or by post-treating the formulated catalystcomprising the MEL or MFI-type zeolites. Preferably, the catalystcomprising MEL or MFI-type zeolites comprises phosphorus as such or in acompound in an elemental amount of from 0.05-10 wt % based on the weightof the formulated catalyst. A particularly preferred catalyst comprisesphosphorus and MEL or MFI-type zeolites having SAR of in the range offrom 60 to 150, more preferably of from 80 to 100. An even moreparticularly preferred catalyst comprises phosphorus and ZSM-5 havingSAR of in the range of from 60 to 150, more preferably of from 80 to100.

It is preferred that the molecular sieves in the hydrogen form are usedin the oxygenate conversion catalyst, e.g., HZSM-22, HZSM-23, andHZSM-48, HZSM-5. Preferably at least 50% w/w, more preferably at least90% w/w, still more preferably at least 95% w/w and most preferably 100%of the total amount of molecular sieve used is in the hydrogen form. Itis well known in the art how to produce such molecular sieves in thehydrogen form.

The catalyst particles used in the process of the present invention canhave any shape known to the skilled person to be suitable for thispurpose, for it can be present in the form of spray dried catalystparticles, spheres, tablets, rings, extrudates, etc. Extruded catalystscan be applied in various shapes, such as, cylinders and trilobes.Spherical particles are normally obtained by spray drying. Preferablythe average particle size is in the range of 1-500 μm, preferably 50-100μm.

The reaction conditions of the oxygenate conversion in step (a) includea reaction temperature from 350 to 750° C., preferably from 450 to 750°C., more preferably from 450 to 700° C., even more preferably 500 to650° C.; and a pressure of from 1-15 bara, preferably from 1-4 bara,more preferably from 1.1-3 bara, and even more preferably from 1.3-2bara.

Suitably, the oxygenate-comprising feed is preheated to a temperature inthe range of from 120 to 550° C., preferably 250 to 500° C. prior tocontacting with the molecular sieve catalyst in step (a).

Preferably, in addition to the oxygenate, an olefinic co-feed isprovided along with and/or as part of the oxygenate feed. Referenceherein to an olefinic co-feed is to an olefin-comprising co-feed. Theolefinic co-feed preferably comprises C4 and higher olefins, morepreferably C4 and C5 olefins. Preferably, the olefinic co-feed comprisesat least 25 wt %, more preferably at least 50 wt %, of C4 olefins, andat least a total of 70 wt % of C4 hydrocarbon species. The olefinicco-feed can also comprise propylene.

The reaction in step (a) may suitably be operated in a fluidized bed,e.g. a dense, turbulent or fast fluidized bed or a riser reactor or adownward reactor system, and also in a fixed bed reactor, moving bed ora tubular reactor. A fluidized bed, e.g. a turbulent fluidized bed, fastfluidized bed or a riser reactor system are preferred. These could bearranged as a single or multiple reactors in parallel or in series.

The superficial velocity of the gas components in a dense fluidized bedwill generally be from 0 to 1 m/s; the superficial velocity of the gascomponents in a turbulent fluidized bed will generally be from 1 to 3m/s; the superficial velocity of the gas components in a fast fluidizedbed will generally be from 3 to 5 m/s; and the superficial velocity ofthe gas components in a riser reactor will generally be from 5 to about25 m/s.

It will be understood that dense, turbulent and fast fluidized beds willinclude a dense lower reaction zone with densities generally above 300kg/m³. Moreover, when working with a fluidized bed several possibleconfigurations can be used: (a) co-current flow meaning that the gas(going upward) and the catalyst travels through the bed in the samedirection, and (b) countercurrent, meaning that the catalyst is fed atthe top of the bed and travels through the bed in opposite directionwith respect to the gas, whereby the catalyst leaves the vessel at thebottom. In a conventional riser reactor system the catalyst and thevapors will travel co-currently.

More preferably, a fluidized bed, in particular a turbulent fluidizedbed system is used. Suitably, in such a moving bed reactor the oxygenatefeed is contacted with the molecular sieve catalyst at a weight hourlyspace velocity of at least 1 hr⁻¹, suitably from 1 to 1000 hr⁻¹,preferably from 1 to 500 hr⁻¹, more preferably 1 to 250 hr⁻¹, even morepreferably from 1 to 100 hr⁻¹, and most preferably from 1 to 50 hr⁻¹.

The reactor in step (a) can also be an OCP reaction zone wherein theolefinic feed is contacted with an zeolite-comprising catalyst underolefin conversion conditions.

Suitably, the olefinic feed comprises C4+ olefins that are converted bycontacting such a feed with a zeolite-comprising catalyst, therebyconverting at least part of the olefins comprising 4 or more carbonatoms to olefins having a lower carbon number, i.e. a olefin having ncarbon atoms is cracked to at least one olefin have m carbon atoms,wherein n and m are integers and m is smaller than n. Preferably, theolefins comprising 4 or more carbon atoms are cracked to at leastethylene and propylene.

Preferably, the olefinic feed is contacted with the zeolite-comprisingcatalyst in step (a) at a reaction temperature of 350 to 1000° C.,preferably from 375 to 750° C., more preferably 450 to 700° C., evenmore preferably 500 to 650° C.; and a pressure from 1 bara to 50 bara,preferably from 1-15 bara. Optionally, such olefinic feed also containsa diluent. Examples of suitable diluents include, but are not limitedto, such as water or steam, nitrogen, paraffins and methane. Under theseconditions, at least part of the olefins in the olefinic feed areconverted to further ethylene and/or propylene.

In an OCP suitably aluminosilicate catalysts are used. Aluminosilicatecatalysts, and in particular zeolite catalysts, have the additionaladvantage that in addition to the conversion of methanol or ethanol,these catalysts also induce the conversion of olefins to ethylene and/orpropylene. Therefore, aluminosilicate catalysts, and in particularzeolite catalysts, are particularly suitable for use as the catalyst inan OCP unit.

The preferences provided herein above for the oxygenate to olefinscatalyst apply mutatis mutandis for the OCP catalyst with the primaryexception that the OCP catalyst always comprises at least one zeolite.

Particular preferred catalysts for the OCP reaction, i.e. convertingpart of the olefinic product, and preferably part of the C4+ hydrocarbonfraction of the olefinic product including olefins, are catalystscomprising at least one zeolite selected from MFI, MEL, TON and MTT typezeolites, more preferably at least one of ZSM-5, ZSM-11, ZSM-22 andZSM-23 zeolites.

The catalyst may further comprise phosphorus as such or in a compound,i.e. phosphorus other than any phosphorus included in the framework ofthe molecular sieve. It is preferred that a MEL or MFI-type zeolitecomprising catalyst additionally comprises phosphorus. The phosphorusmay be introduced by pre-treating the MEL or MFI-type zeolites prior toformulating the catalyst and/or by post-treating the formulated catalystcomprising the MEL or MFI-type zeolites. Preferably, the catalystcomprising MEL or MFI-type zeolites comprises phosphorus as such or in acompound in an elemental amount of from 0.05 to 10 wt % based on theweight of the formulated catalyst. A particularly preferred catalystcomprises phosphorus and MEL or MFI-type zeolite having SAR of in therange of from 60 to 150, more preferably of from 80 to 100. An even moreparticularly preferred catalyst comprises phosphorus and ZSM-5 havingSAR of in the range of from 60 to 150, more preferably of from 80 to100.

Preferably, the oxygenate to olefins catalyst and the olefin crackingcatalyst are the same zeolite-comprising catalyst.

Also an OCP process may suitably be operated in a fluidized bed, e.g. afast fluidized bed or a riser reactor or a downward reactor system, andalso in a fixed bed reactor, moving bed reactor or a tubular reactor. Afluidized bed, e.g. a fast fluidized bed or a riser reactor system arepreferred.

The olefins and at least partially coked catalyst as obtained in step(a) will be separated. The separation can be carried out by one or morecyclone separators. Such one or more cyclone separators may be locatedinside, partly inside and partly outside, or outside the reactor used instep (a). Such cyclone separators are well known in the art. Cycloneseparators are preferred, but also methods for separating the catalystfrom the olefins can be used that apply plates, caps, elbows, and thelike.

In step (b), the effluent comprising olefins as obtained in step (a) areseparated into at least a first olefinic product fraction comprisingpropylene, and a second olefinic product fraction, preferably comprisingolefins having 4 or more carbon atoms. Preferably, the first olefinicfraction comprises in the range of from 50 to 100 wt %, more preferablyof from 80 to 100 wt %, even more preferably 95 to 100 wt % ofpropylene, based on the hydrocarbons in the first olefinic productfraction. Suitably, at least part of the second olefinic productfraction is recycled to step (a) for use as an olefinic co-feed.

Preferably, at least 70 wt % of the olefinic co-feed, during normaloperation, is formed by the recycle stream of the second olefinicproduct fraction containing olefins having 4 or more carbon atoms,preferably at least 90 wt % of olefinic co-feed, based on the wholeolefinic co-feed, is formed by such a recycle stream.

In order to maximize production of ethylene and propylene, it isdesirable to optimize the recycle of olefins having more than 4 carbonatoms in the effluent to the OTO or olefin cracking process. This can bedone by recycling at least part of the second olefinic fractioncontaining olefins having 4 or more carbon atoms, preferably the C4-C5hydrocarbon fraction, more preferably the C4 hydrocarbon fraction, tothe OTO or OCP reaction zone in step (a). Suitably, however, a certainpart thereof, such as between 1 and 5 wt %, is withdrawn as purge, sinceotherwise saturated hydrocarbons, in particular C4's (butane) wouldbuild up in the process, which are substantially not converted under theOTO or OCP reaction conditions.

The preferred molar ratio of oxygenate in the oxygenate feed to olefinin the olefinic co-feed provided to the OTO reaction zone in step (a)depends on the specific oxygenate used and the number of reactiveoxygen-bonded alkyl groups therein. Preferably the molar ratio ofoxygenate to olefin in the total feed lies in the range of 20:1 to 1:10,more preferably in the range of 18:1 to 1:5, still more preferably inthe range of 15:1 to 1:3, even still more preferably in the range of12:1 to 1:3.

Although the second olefinic fraction containing olefins having 4 ormore carbon atoms as separated from the effluent comprising olefins asrecovered in step (b) may be recycled as an olefinic co-feed to the OTOreaction zone in step (a), alternatively at least part of the olefins inthe second olefinic fraction may be converted to ethylene and/orpropylene by contacting such C4+ hydrocarbon fraction in a separateolefin cracking unit with a zeolite-comprising catalyst. This isparticularly preferred when the molecular sieve catalyst in step (a)comprises a least one SAPO, AlPO, or MeAlPO type molecular sieve,preferably SAPO-34. These catalysts are less suitable for convertingolefins. Preferably, the C4+ hydrocarbon fraction is contacted with thezeolite-comprising catalyst at a reaction temperature of 350 to 1000°C., preferably from 375 to 750° C., more preferably 450 to 700° C., evenmore preferably 500 to 650° C.; and a pressure from 1 bara to 50 bara,preferably from 1-15 bara. Optionally, such a stream comprising C4+olefins also contains a diluent. Examples of suitable diluents include,but are not limited to, such as water or steam, nitrogen, and methane.Under these conditions, at least part of the olefins in the C4+hydrocarbon fraction are converted to further ethylene and/or propylene.The further ethylene and/or propylene may be combined with the ethyleneand/or propylene as obtained in step (b). Such a separate process stepdirected at converting C4+ olefins to ethylene and propylene is, as willbe clear from the foregoing, also referred to as an olefin crackingprocess (OCP).

In such a subsequent separate OCP suitably zeolite-comprising catalystsare used. Catalyst suitable for an olefin cracking process have beendescribed herein above and may be used for the additional separate OCPprocess step.

Preferably, the catalyst used in step (a) and the separate OCP unit arethe same zeolite-comprising catalyst.

Preferably, at least part of the second olefinic product fractioncomprising olefins having 4 or more carbon atoms as obtained in step (b)is first fractionated to obtain at least a third olefinic productfraction comprising C4 olefins and a fourth olefinic product fractioncomprising olefins having 5 or more carbon atoms, wherein at least partof the fourth fraction is provided to the separate olefin cracking unit,while at least part of the third olefinic product fraction is recycledas recycle stream to step (a). By converting the olefins having 5 ormore carbon atoms separately in the separate OCP unit, the condition inthe separate OCP unit can be selected to obtain an optimal converse ofolefins having more than 5 carbon atoms.

At least partially coked catalyst as obtained in step (a) can be passedto a regenerator. Suitably, the at least partially coked catalyst asobtained in step (a) is passed in its entirety or a portion of it to theregenerator. The molecular sieve catalyst to be used in accordance withthe present invention deactivates in the course of the process withtime, due to issues around coke deposition and hydrothermal stability.Hence, the molecular sieve catalyst needs to be regenerated in order toat least partly remove coke from the coked catalyst as obtained in step(a). Conventional catalyst regeneration techniques can be employed toremove the coke. It is not necessary to remove all the coke from thecatalyst as it is believed that a preset amount of residual coke mayenhance the catalyst performance and additionally, it is believed thatcomplete removal of the coke may also lead to degradation of themolecular sieve.

In order to regenerate at least part of the at least partially cokedcatalyst an oxygen-containing gas will be introduced in the regenerator,thereby producing a gaseous mixture and at least partially regeneratedcatalyst. The oxygen-containing gas may be chosen from oxygen and air.Also mixtures can suitably be used of these oxygen-containing gases.Preferably, the oxygen-containing gas comprises oxygen, more preferablyair is used as the oxygen-containing gas.

The regeneration will be carried out under conditions of temperature,pressure and residence time that is usually applied in regenerationprocesses to burn coke from catalysts. Suitably, between 0.01-5 wt % ofthe coke present on the at least partially coked catalyst is removedfrom the catalyst during regeneration.

Suitably, the regeneration is carried out at a temperature in the rangeof from 580-800° C., preferably in the range of from 600-750° C., morepreferably in the range of from 620-680° C., and a pressure in the rangeof from 1-5 bara, preferably in the range of from 1-3 bara, morepreferably in the range of from 1.3-2 bara. The regeneration cansuitably be carried out in a fixed bed, a fluidized bed such as a dense,turbulent or fast fluidized bed or in a riser or downward regenerator.Preferably, the regeneration is carried out in a turbulent fluidizedbed.

Suitably, the regeneration can be carried out in a periodical manner orcontinuous manner. Preferably, the regeneration is carried out in acontinuous manner.

The hydroformylation process to be used in step (c) can be any knownhydroformylation process. In a hydroformylation process, an olefin isconverted in the presence of a catalyst with carbon monoxide andhydrogen to an aldehyde having at least one carbon atom more than theolefin. For instance, propylene may be converted to butyraldehyde in ahydroformylation process.

In the hydroformylation process preferably use is made of catalyst whichcomprises a transition metal in complex combination ligand(s), such asan organophosphine and/or organophosphate, and optionally carbonmonoxide. Suitable transition metals that can be used in step (c)include rhodium, cobalt, iridium, ruthenium, iron, nickel, palladium,platinum, osmium and any mixture thereof. Preferred transition metalsare rhodium, cobalt, iridium and ruthenium, more preferably rhodium,cobalt and ruthenium, and most preferably rhodium.

Suitably, a hydrogen to carbon monoxide molar ratio is used in range offrom 1:10 to 100:1, preferably in the range of from 1:10 to 10:1.

In accordance with the present invention the molar ratio of hydrogen tocarbon monoxide in the hydroformylation process, wherein the intendedproduct is an alcohol, is preferably in the range of from 2.5:1 to1:2.5, more preferably in the range of from 2.2:1 to 1:2.2

Suitably, water is added into the reactor system to be used in thehydroformylation process.

The hydroformylation process of the present invention may be carried outas a batch process or as a continuous process.

The hydroformylation process in step (c) can suitably be carried out inone or two or more reaction zones. The term “reaction zone”, as usedherein, refers to a controlled environment which contains the reactionmixture, wherein the hydroformylation process of the present inventionmay occur. A reaction zone can be, for example, a reactor or a sectionof a reactor in which the reaction conditions, including temperature,pressure and, optionally, concentration of reagents, may be controlledindependently from the rest of the reactor. Typically, the reactionzones are reactors.

The number of reaction zones used in order to carry out the process ofthe present invention is not critical. When the reaction zones of theprocess of the present invention are reactors, the reactors may beisolated reactors or a series of reactors which are linked together.Preferably the process of the present invention is carried out in atleast two reactors linked in series. By the term “linked in series” asused herein, it is meant a series of separate reaction zones which arelinked together so as to form a continuous reaction chain where thereaction mixture passes continuously from one reaction zone to the nextunder controlled temperature and pressure conditions, wherein thetemperature and pressure of the individual reaction zones may be setindependently.

The hydrogen and carbon monoxide may be introduced into the process ofthe present invention as two distinct streams, i.e. a hydrogen gas feedstream and a carbon monoxide gas feed stream, or as a combined feedstream, e.g. a syngas feed stream. ‘Syngas’ as used herein refers to amixture of carbon monoxide and hydrogen generated, for example, by thegasification of a carbon-containing fuel.

Commercially or industrially available combined hydrogen and carbonmonoxide streams (e.g. syngas) can be used in the hydroformylationprocess in step (c). Generally such gas streams contain a ratio ofhydrogen to carbon monoxide of greater than 1.65:1. Optionally, water isadded to perform a Ni catalyzed water gas shift reaction to adjust themolar ratio of hydrogen to carbon monoxide. Optionally, CO₂ can beremoved from the syngas before use in step (c). A suitable combinedhydrogen/carbon monoxide feed stream may be provided by a method thatreduces the level of hydrogen in the stream relative to the level ofcarbon monoxide in such a stream. This may involve adding carbonmonoxide or removing hydrogen from the combined hydrogen and carbonmonoxide stream. Hydrogen can be removed from a combined hydrogen andcarbon monoxide stream by any suitable method, such as absorption orreaction.

In one embodiment of the present invention, a combined hydrogen/carbonmonoxide feed stream is provided for the hydroformylation process byusing a combined hydrogen/carbon monoxide feed stream which comprises acombined hydrogen/carbon monoxide feed stream which has already beenused in a reaction that reduces the ratio of hydrogen to carbon monoxidein said combined gas feed stream. Preferably, the combinedhydrogen/carbon monoxide stream has already been subjected to ahydroformylation reaction. More preferably, the combined hydrogen/carbonmonoxide stream is a recycled stream from the hydroformylation processas carried out in step (c).

It will be understood by the skilled person that, as the reactionproceeds, the molar ratio of hydrogen to carbon monoxide will varythroughout the reaction environment. The ratio of hydrogen to carbonmonoxide in the reaction environment may also vary if a further hydrogengas feed stream and/or a combined hydrogen/carbon monoxide feed streamis introduced into a second and/or a later reaction zone(s).

The hydroformylation process in step (c) may be carried out over a widerange of temperatures. Suitable temperatures for the reactionenvironment are in the range of from 50 to 220° C., preferably in therange of from 80 to 180° C., more preferably in the range of from 90 to140° C.

The hydroformylation process in step (c) may be carried out at variouspressures. Consequently, hydroformylation in accordance with the processof the present invention may typically be carried out at pressures inthe range of from 0.1-200 bar, preferably in the range of from 10-100bar.

The product stream as obtained in step (c) will comprise aldehyde,catalyst, by-products and any unconsumed reactants. The product streamas obtained in step (c) may be subjected to suitable catalyst andproduct separating means comprising one or more steps, for example,stratification, solvent extraction, distillation, fractionation,adsorption, filtration, etc. The specific method of product and catalystseparation employed will be governed to some extent by the specificmetal ion in complex combination with carbon monoxide and ligand(s) andreactants charged. Catalyst or components thereof, as well as unconsumedreactants, by-products, aldehyde products, and solvent, when employed,may be recycled in part or in their entirety to the hydroformylationprocess. For example, a part of an aldehyde reaction product may, ifdesired, be recycled to the hydroformylation process in step (c) tofunction as solvent and/or diluent and/or suspending medium for thecatalyst and the catalyst components. Part of the heavy ends by-productas obtained in the hydroformylation process in step (c) may also berecycled to the reaction environment in order to aid solution and/orsuspension of the catalyst. Further, part or all of any aldehydeproduced, may optionally be recycled to the hydroformylation process,but preferably is subjected to hydrogenation conditions in a separatereaction environment in the presence of a metal-based hydrogenationcatalyst In a preferred embodiment of the present invention, the usedcatalyst in the hydroformylation process is recycled to the reactionenvironment as a feed stream for re-use.

In a preferred embodiment of the present invention, before any additionof water, the stream to be recycled comprises at most 300 ppmw, morepreferably at most 100 ppmw, even more preferably at most 50 ppmw, mostpreferably at most 20 ppmw of water.

Additional preformed catalyst, or separate components of the catalystcapable of producing the active complex in situ, may be added to theseparated material which is being recycled to the reaction environmentor alternatively to the product stream exiting the reaction environmentbefore said product stream is subjected to separating means. Further,such preformed catalyst, or separate components of the catalyst capableof producing the active complex in situ, may be added directly to thereactor or into the olefinic feed stream to step (c).

The water is preferably added into the reaction system in an amount ofat least 0.05 wt %, more preferably at least 0.075 wt %, most preferablyat least 0.1 wt %, based on the total weight of the reaction mixture.The water is preferably added into the reaction system in an amount ofat most 10 wt %, more preferably at most 5 wt %, most preferably at most2 wt %, based on the total weight of the reaction mixture.

In a preferred embodiment, the hydroformylation process in step (c) iscarried out as a continuous process and water is continually added intothe reactor system in order to maintain the amount of water at thedesired level. The water to be added into the reactor system may also beadded to the reactor system as an aqueous solution of one or more salts.Suitable salts include, but are not limited to KOH, NaOH, NaSH and Na2S.The water may be added at any point in the reactor system. In oneembodiment of the present invention, the water is added at the beginningof the reactor system. In order to achieve this, the water may be addedinto the reaction environment as a separate feed stream or it may beadded to one of the feed streams containing one or more of the otherreactants. For example, the water may be added to the recycled catalystfeed stream. Alternatively, it may be preferable to add the water to afeed stream comprising olefinic feedstock or into a feed streamcomprising hydrogen and/or carbon monoxide.

In another embodiment of the present invention, the water is added tothe reactor system at a point where at least part of the olefinicfeedstock has undergone conversion to form aldehydes. This involvesaddition of the water at a point part of the way along the reactionenvironment. The water may be added at the start of or part of the wayalong any of the reaction zones. In the case where the reactionenvironment comprises one or more reactors, this may be achieved byaddition of the water at a point part of the way along an individualreactor, or, where there is more than one reactor, at a point betweentwo reactors. Due to the increased solubility of water in the aldehydeproducts in comparison to the olefinic feedstock, this embodiment hasthe advantage that more water may be added at this stage without riskingflooding the reactor and quenching the reaction.

In a further embodiment, the water may be added to the output stream ofthe reactor system. Suitably, the water is added to the reactor systemwhile the hydroformylation reaction is proceeding.

The feed stream for the hydroformylation process in step (c) compriseshydrogen, carbon monoxide, the first olefinic product fraction,catalyst, or catalyst components, optionally one or more recyclestreams, also optionally one or more dopants and, optionally, water.

Suitable dopants include, but are not limited to, NaSH, Na₂S and organicsulfur-containing additives including thiols, disulfides, thioethers andthiophenes.

The feed stream for the hydroformylation process may be introduced intothe reaction environment as discreet feed streams or may be mixedtogether in any combination before entering the reaction environment.

Admixtures of promoters and/or stabilizers may also be included in thehydroformylation process in step (c). Thus, minor amounts of phenolicstabilizers such as hydroquinone and/or alkaline agents such ashydroxides of alkali metals, for example NaOH and KOH, may be added tothe reaction environment.

The ratio of catalyst to the first olefinic product fraction to behydroformylated is generally not critical and may vary widely. It may bevaried to achieve a substantially homogeneous reaction mixture. Solventsare therefore not required. However, the use of solvents which areinert, or which do not interfere to any substantial degree with thedesired hydroformylation reaction under the conditions employed, may beused. Saturated liquid hydrocarbons, for example, may be used as solventin the process, as well as alcohols, ethers, acetonitrile, sulfolane,and the like. The molar ratio of catalyst to the first olefinic productfraction in the reaction zone of the hydroformylation process at anygiven instant is typically at least about 1:1000000, preferably at leastabout 1:10000, and more preferably at least about 1:1000, and preferablyat most about 10:1. A higher or lower ratio of catalyst to the firstolefinic product fraction may, however, be used, but in general it willbe less than 1:1.

The organophosphine and/or organophosphite modified transition metalhydroformylation catalyst for use in step (c) may comprise a transitionmetal in complex combination with carbon monoxide and an organophosphineligand and/or organophosphate ligand. By the term “complex combination”as used herein, is meant a coordination compound formed by the union ofone or more carbon monoxide and organophosphine and/or organophosphitemolecules with one or more transition metal atoms. In its active formthe suitable organophosphine and/or organophosphite modified transitionmetal hydroformylation catalyst contains one or more metal components ina reduced valence state.

Suitable organophosphine or organophosphite ligands include those havinga trivalent phosphorus atom having one available or unshared pair ofelectrons. Any essentially organic derivative of trivalent phosphoruswith the foregoing electronic configuration is a suitable ligand for thecobalt catalyst.

Organic radicals of any size and composition may be bonded to thephosphorus atom. For example the organophosphine or organophosphiteligand may comprise a trivalent phosphorus having aliphatic and/orcycloaliphatic and/or heterocyclic and/or aromatic radicals satisfyingits three valencies. These radicals may contain a functional group suchas carbonyl, carboxyl, nitro, amino, hydroxy, saturated and/orunsaturated carbon-to-carbon linkages, and saturated and/or unsaturatednon-carbon-to-carbon linkages.

It is also suitable for an organic radical to satisfy more than one ofthe valencies of the phosphorus atom, thereby forming a heterocycliccompound with a trivalent phosphorus atom. For example, an alkyleneradical may satisfy two phosphorus valencies with its two open valenciesand thereby form a cyclic compound. Another example would be an alkylenedioxy radical that forms a cyclic compound where the two oxygen atomslink an alkylene radical to the phosphorus atom. In these two examples,the third phosphorus valency may be satisfied by any other organicradical.

Another type of structure involving trivalent phosphorus having anavailable pair of electrons is one containing a plurality of suchphosphorus atoms linked by organic radicals. This type of a compound istypically called a bidentate ligand when two such phosphorus atoms arepresent, a tridentate ligand when three such phosphorus atoms arepresent.

The organophosphine and/or organophosphite modified transition metalhydroformylation catalyst to be used in step (c) can be prepared by adiversity of methods well known to those skilled in the art. Aconvenient method is to combine a transition metal salt, organic orinorganic, with the desired phosphine ligand, for example, in liquidphase followed by reduction and carbonylation. Suitable transition metalsalts comprise, for example, transition metal carboxylates such asacetates, octanoates, etc. as well as transition metal salts of mineralacids such as chlorides, fluoride, sulfates, sulfonates, etc. as well asmixtures of one or more of these transition salts. The valence state ofthe transition metal may be reduced and the transition metal-containingcomplex formed by heating the solution in an atmosphere of hydrogen andcarbon monoxide. The reduction may be performed prior to the use of theorganophosphine modified transition metal hydroformylation catalysts orit may be accomplished in-situ with the hydroformylation process in thehydroformylation environment. Alternatively, the organophosphinemodified transition metal hydroformylation catalysts can be preparedfrom a carbon monoxide complex of a transition metal.

Preferably, the first olefinic product comprises propylene and thealdehydes produced are at least normal butyraldehyde andiso-butyraldehyde.

In step (d) of the process at least part of the aldehydes as obtained instep (c) are separated into at least a first product fraction ofaldehydes and a second product fraction of aldehydes. In step (d), thealdehydes as obtained in step (c) are separated into normal aldehydesand iso-aldehydes. This may be done using conventional distillationseparation processes. Such processes are well known in the art and donot need further explanation. Preferably, the first product fraction ofaldehydes as obtained in step (d) comprises iso-butyraldehyde and thesecond product fraction of aldehydes as obtained in step (d) comprisesnormal butyraldehyde. Preferably, the aldehydes are separated in afraction enriched in normal aldehydes and depleted in iso-aldehydes anda fraction enriched in iso-aldehydes and depleted in normal aldehydes.

Preferably, first product fraction of aldehydes as obtained in step (d)comprises iso-butyraldehyde. More preferably the first product fractionof aldehydes comprises in the range of from 80 to 100 wt % ofiso-butyraldehyde based on the aldehydes in the first product fractionof aldehydes.

Preferably, second product fraction of aldehydes as obtained in step (d)comprises normal butyraldehyde. More preferably the second productfraction of aldehydes comprises in the range of from 90 to 100 wt %,more preferably of from 99 to 100 wt %, even more preferably 99.9 to 100wt % of normal butyraldehyde based on the aldehydes in the secondproduct fraction of aldehydes.

In step (e), at least part of the aldehydes in the first and/or secondproduct fraction of aldehydes as obtained in step (d) are hydrogenatedto form a first product fraction of alcohols and/or a second productfraction of alcohols. Preferably, at least part of the first productfraction of aldehydes is hydrogenated and the first product fraction ofalcohols as obtained in step (e) comprises an iso-alcohol, preferablyiso-butyl alcohol.

In step (e) aldehydes as obtained in step (c) are hydrogenated withhydrogen to form alcohols. Depending on the aldehyde that ishydrogenated the alcohols formed are iso-alcohol and normal alcohol,preferably isobutyl-alcohol and normal butyl-alcohol.

The catalyst to be used in step (e) is metal-based catalyst. Suitablemetals to be used include platinum, palladium, ruthenium, copper,chromium and nickel. Preferably, use is made in step (e) of anickel-based catalyst. Preferably, step (e) is carried at a temperaturein the range of from 100-150° C. and a pressure in the range of from 2-5bar. Hydrogenation process are well known in the art and do not needfurther explanation.

Preferably, at least part of the second product fraction comprisingaldehydes is withdrawn from the process as an aldehyde product,preferably comprising normal butyraldehyde.

Equally preferably, the aldehydes in the second product fractioncomprising aldehydes are hydrogenated and at least part of the secondproduct fraction comprising alcohols is withdrawn from the process as analcohol product, preferably comprising normal butyl-alcohol.

In step (f) at least part of the first or second product fraction ofalcohols are recycled to step (a). Depending on the desired aldehydeand/or alcohol product either the iso alcohols or the normal alcoholsare recycled. Any alcohols recycled to step (a) are subsequentlyconverted at least in part back to propylene. This propylene may be usedas part of the first olefinic product to produced further aldehydes andoptionally alcohols. Preferably, at least part of the first productfraction of alcohols, which comprises isobutyl-alcohol is recycled tostep (a). More preferably, the entire first product fraction of alcoholswhich comprises isobutyl-alcohol is recycled to step (a).

The process according to the present invention integrates an OTO processfor the production of olefins, in particular propylene, and a subsequenthydroformylation respectively hydroformylation/hydrogenation process forconverting the propylene to butyraldehyde and butanol. Typically, thehydroformylation respectively hydroformylation/hydrogenation processproduces a mixture of aldehydes or alcohols comprising more than oneisomers of the aldehydes or alcohol such as in case of butyraldehyde,normal butyraldehyde and iso-butyraldehyde and in the case of butanol,normal butyl-alcohol and isobutyl-alcohol. A particular advantage ofthis integration is that the undesired isomer(s) of the aldehyde oralcohol may be recycled back, i.e. in the case of the aldehyde afterhydrogenation to the corresponding alcohol, to the OTO process to beconverted at least in part back to propylene. As such it is possible toproduce essentially only the desired aldehyde or alcohol isomer. Due tothe recycle of the undesired isomer it is not necessary that thehydroformylation respectively hydroformylation/hydrogenation processproduces an aldehyde or alcohol mixture that is enriched in the desiredaldehyde or alcohol, allowing a much broader and economic choice inpossible hydroformylation respectively hydroformylation/hydrogenationprocesses and catalyst.

A further advantage of the integrated process according the invention isthat part of the alcohol, in particular butanol, recycled back to step(a) is converted into ethylene. As the butanol was produced, viabutyraldehyde from propylene, part of the propylene is converted tofurther ethylene, which is a valuable chemical feedstock.

The invention will be further described by way of the followingnon-limiting example.

EXAMPLE

Two catalysts, comprising 40 wt % zeolite, 36 wt % kaolin and 24 wt %silica were tested to show their ability to convert anisobutyl-alcohol-containing feedstock to an olefinic product. To testthe catalyst formulations for catalytic performance, the catalysts werepressed into tablets and the tablets were broken into pieces and sieved.In the preparation of the first catalyst sample ZSM-23 zeolite powderwith a silica to alumina molar ratio (SAR) 46, and ZSM-5 zeolite powderwith a SAR of 80 were used in the ammonium form in the weight ratio50:50. Prior to mixing the powders, the ZSM-5 zeolite powder was treatedwith phosphorus, resulting in a catalyst that has only one zeolitepre-treated with phosphorus. Phosphorus was deposited on a ZSM-5 zeolitepowder with a silica-to-alumina ratio of 80 by means of impregnationwith an acidic solution containing phosphoric acid to obtain a ZSM-5treated zeolite powder containing 2.0 wt % P. The ZSM-5 powder wascalcined at 550° C. Then, the powder mix was added to an aqueoussolution and subsequently the slurry was milled. Next, kaolin clay and asilica sol were added and the resulting mixture was spray dried whereinthe weight-based average particle size was between 70-90 μm. The spraydried catalysts were exposed to ion-exchange using an ammonium nitratesolution. Then, phosphorus was deposited on the catalyst by means ofimpregnation using acidic solutions containing phosphoric acid (H₃PO₄).The concentration of the solution was adjusted such to impregnate 1.0 wt% of phosphorus on the catalyst. After impregnation the catalysts weredried at 140° C. and were calcined at 550° C. for 2 hours. The finalformulated catalyst thus obtained is further referred to as catalyst 1.

Another formulated catalyst was prepared as described herein above forcatalyst 1, with the exceptions that only ZSM-5 with a SAR of 80 wasused and which was not treated with phosphorus prior to spraydrying. Theconcentration of the phosphorus impregnation solution was adjusted suchto impregnate 1.5 wt % of phosphorus on the catalyst formulation. Thefinal formulated catalyst thus obtained is further referred to ascatalyst 2.

The phosphorus loading on the final catalysts is given in Table 1 as wt% of elemental phosphorus in any phosphor species, based on the totalformulated catalyst, and was determined by elemental analysis. Theamount of phosphorus is based on the elemental weight of phosphorus(which does not need to be in elemental form though) and not on thetotal weight of phosphorus species present. This may be determined byelemental analysis and is also referred to as elemental phosphorusloading.

A stream of isobutyl-alcohol, comparable to an isobutyl-alcohol streamobtainable from a hydroformylation process, was provided. Theisobutyl-alcohol in the presence and absence of methanol or methanol andbutene-1 was reacted over the catalysts which were tested to determinetheir selectivity towards olefins, mainly ethylene and propylene. Forthe catalytic testing, a sieve fraction of 60-80 mesh was used. Prior toreaction, the molecular sieves were treated ex-situ in air at 550° C.for 2 hours.

The reaction was performed using a quartz reactor tube of 1.8 mminternal diameter. The molecular sieve samples were heated in nitrogento the reaction temperature and a mixture consisting of 3 vol %butene-1, 6% vol % methanol balanced in N₂ was passed over the catalystat atmospheric pressure (1 bar). In another experiment 3 vol % ofisobutyl-alcohol, 6% vol % methanol balanced in N₂ was passed over thecatalyst at atmospheric pressure (1 bar). In yet another experiment 3vol % isobutyl-alcohol balanced in N₂ was passed over the catalyst atatmospheric pressure (1 bar). The Gas Hourly Space Velocity (GHSV) isdetermined by the total gas flow over the zeolite weight per unit time(ml·gzeolite⁻¹·h⁻1). The gas hourly space velocity used in theexperiments was 19000 (ml·gzeolite⁻¹·h⁻¹). The effluent from the reactorwas analyzed by gas chromatography (GC) to determine the productcomposition. The composition has been calculated on a weight basis ofall hydrocarbons analyzed. The composition has been defined by thedivision of the mass of specific product by the sum of the masses of allproducts. The effluent from the reactor obtained at several reactortemperatures was analyzed. The results are shown in Table 1. Theethylene and propylene obtained are then subjected to thehydroformylation process. Iso-butyraldehydes obtained hydroformylationprocess are hydrogenated to isobutanol. This obtainable isobutanol iscomparable to the isobutanol provided in this example.

It will be clear from the table 1 that the isobutanol is convenientlyrecycled to an OTO process to be converted to propylene, which maysubsequently be used as a feed to a hydroformylation process. Inaddition, ethylene may formed by the conversion of isobutanol in an OTOprocess.

TABLE 1 C4 C5 C6 and Temp C2 = C3 = total total heavier LE C4 sat/C4Catalyst Feed Vol % ° C. wt % wt % wt % wt % wt % wt % total wt/wtCatalyst 1 C4 =/MeOH/ 0/0/3 575 8.37 22.81 64.73 2.86 1.15 0.09 1.36iC4OH Catalyst 1 C4 =/MeOH/ 0/6/3 575 17.07 50.97 27.62 2.02 2.15 0.172.39 iC4OH Catalyst 1 C4 =/MeOH/ 3/6/0 575 16.07 52.81 26.81 1.95 2.060.29 1.72 iC4OH Catalyst 2 C4 =/MeOH/ 0/0/3 575 12.91 32.65 49.65 2.052.48 0.25 3.01 iC4OH Catalyst 2 C4 =/MeOH/ 0/6/3 575 19.56 50.53 23.911.74 3.70 0.55 4.09 iC4OH Catalyst 2 C4 =/MeOH/ 3/6/0 575 18.16 51.9323.62 1.63 3.88 0.77 2.64 iC4OH Catalyst 1 C4 =/MeOH/ 0/0/3 525 8.3030.58 52.70 5.64 2.75 0.03 2.72 iC4OH Catalyst 1 C4 =/MeOH/ 0/6/3 52513.73 49.31 28.41 4.08 4.41 0.05 4.24 iC4OH Catalyst 1 C4 =/MeOH/ 3/6/0525 13.16 50.98 27.91 3.97 3.95 0.04 2.93 iC4OH Catalyst 2 C4 =/MeOH/0/0/3 525 13.16 41.77 37.70 3.62 3.57 0.17 5.08 iC4OH Catalyst 2 C4=/MeOH/ 0/6/3 525 16.76 49.29 24.70 3.33 5.53 0.39 5.77 iC4OH Catalyst 2C4 =/MeOH/ 3/6/0 525 15.94 50.68 24.54 3.11 5.15 0.58 4.09 iC4OH

The which is claimed is:
 1. A process for the production of aldehydesand/or alcohols, which process comprises the steps of: (a) reacting anoxygenate and/or olefinic feed in a reactor in the presence of amolecular sieve catalyst to form an effluent comprising olefins,comprising propylene; (b) separating the effluent comprising olefins asobtained in step (a) into at least a first olefinic product fractioncomprising propylene and a second olefinic product fraction; (c)subjecting at least part of the first olefinic product fraction asobtained in step (b) to a hydroformylation process to form aldehydes;(d) separating at least part of the aldehydes as obtained in step (c)into at least a first product fraction of aldehydes and a second productfraction of aldehydes; (e) hydrogenating at least part of the aldehydesin the first and/or second product fraction of aldehydes as obtained instep (d) to form a first product fraction of alcohols and/or a secondproduct fraction of alcohols; and (f) recycling at least part of thefirst and/or second product fraction of alcohols obtained in step (e) tostep (a).
 2. The process according to claim 1, wherein the first productfraction of aldehydes as obtained in step (d) comprisesiso-butyraldehyde and the second product fraction of aldehydes asobtained in step (d) comprises normal butyraldehyde.
 3. The processaccording to claim 1, wherein at least part of the first productfraction of aldehydes is hydrogenated and the first product fraction ofalcohols as obtained in step (e) comprises an iso-alcohol.
 4. Theprocess according to claim 1, wherein at least part of the first productfraction of alcohols is recycled in step (f) to step (a).
 5. The processaccording to claim 4, wherein the entire first product fraction ofalcohols is recycled to step (a).
 6. The process according to claim 1,wherein at least part of the second product fraction comprisingaldehydes is withdrawn from the process as an aldehyde product.
 7. Theprocess according to claim 1, wherein at least part of the secondproduct fraction comprising alcohols is withdrawn from the process as analcohol product.
 8. The process according to claim 1, wherein themolecular sieve catalyst comprises a zeolite having at least 10-memberedring channels.
 9. The process according to claim 8, wherein the zeoliteis a zeolite of the MFI-type, the MEL-type, the MTT-type, the TON-typeor any mixture thereof.
 10. A process according to claim 1, wherein instep (c) the first olefinic fraction is contacted with carbon monoxideand hydrogen in the presence of a hydroformylation catalyst.
 11. Theprocess according to claim 10, wherein the hydroformylation catalystcomprises rhodium.
 12. The process according to claim 1, wherein theoxygenate feed comprises methanol or dimethylether.
 13. The processaccording to claim 1, wherein the reaction in step (a) is conducted at atemperature from 350 to 750° C.
 14. The process according to claim 1,wherein the effluent comprising olefins as obtained in step (a)comprises ethylene and propylene.
 15. The process according to claim 1,wherein the first olefinic product fraction as obtained in step (b)comprises in the range of from 50 to 100 wt % of propylene, based on thehydrocarbons in the first olefinic product fraction.